undefined method `size' for nil:NilClass (NoMethodError)

/usr/local/apache/htdocs/common/tdiary/index.rb:73
/home/ahorag01/public_html/nishigifu/r-diary/index.rb:2:in `require'
/home/ahorag01/public_html/nishigifu/r-diary/index.rb:2